Display and move in an area at a time instead of the whole map

[half-ogre]

In BrowserQuest, the map is broken up into areas. You show only an area at a time, and when the sprite moves to an area's edge (and there is an adjacent area on that edge), you are moved to the adjacent area. This will require reading the area info from the TMX file.

[half-ogre]

BrowserQuest doesn't handle the display being resized smaller than the area size well at all, at least on a desktop client (I'm guessing it handles it better on mobile). Fortunately, we can handle this better. In windowed mode, I'm thinking we just always size the window so that it fits the area nicely. In full screen, we choose a resolution that works well for the area size. We can scale down as needed, although that should almost never be needed given the size of an area and the small tile size of 16px.